There have been many proposals in the past to construct buildings with a series of interconnected re-enforced concrete panels, some of which are prefabricated in a factory and brought to the site such as U.S. Pat. Nos. 4,691,490, 4,934,121 or 4,751,803 while others or poured on site into forms and raised by heavy equipment to construct large buildings such as warehouses or the like. While many proposals have been successful over the years, each embodiment has limitations and inherent problems which as yet have not been totally satisfactory in many cases such as the manner of attaching the panels together to allow for expansion and contraction, cold spots, means of incorporating insulation as well as providing for plumbing, electrical boxes, air conditioning, etc. The present invention addresses these and other problems.